Neurocrine Biosciences, Inc. v. Spruce Biosciences Inc

This is an active Post-Grant Review (PGR) proceeding initiated by Neurocrine Biosciences, Inc. challenging the validity of US Patent 12,569,491 before the Patent Trial and Appeal Board (PTAB) of the U.S. Patent and Trademark Office. The petition was filed on June 18, 2026, and is currently awaiting a decision on institution.

Neurocrine Biosciences, Inc. is an American biopharmaceutical company founded in 1992, headquartered in San Diego, California. It focuses on developing and commercializing treatments for neurological and endocrine-related diseases and disorders. Its portfolio includes FDA-approved treatments for conditions such as tardive dyskinesia, Huntington's disease chorea, and classic congenital adrenal hyperplasia (CAH), including a product named CRENESSITY™, which is a CRF1 receptor antagonist used to treat classic CAH. Spruce Biosciences Inc., the patent owner, is a late-stage biopharmaceutical company based in South San Francisco, California, also concentrating on developing novel therapies for rare endocrine disorders. Its lead product candidate, Tildacerfont, is being developed as a potential first FDA-approved therapy for CAH, and the company is currently conducting Phase 2/3 clinical trials for it.

The patent at issue, US Patent 12,569,491, likely pertains to the use of CRF1 receptor antagonists in the treatment of congenital adrenal hyperplasia, given the context of previous litigation between these parties. A more detailed technical sketch of the patent would require reviewing its claims and specification, but it broadly covers methods or compositions related to addressing CAH. The procedural posture is a PGR at the PTAB, an administrative body within the USPTO, known for its expertise in patent law and technology, offering a specialized forum for challenging patent validity outside of district court litigation.

This case is notable due to the intense competition between Neurocrine Biosciences and Spruce Biosciences in the market for congenital adrenal hyperplasia treatments. Neurocrine, already having an FDA-approved CAH treatment, has a history of proactively challenging Spruce's patents related to CAH. For instance, Neurocrine previously petitioned for PGRs against other Spruce patents (U.S. Patents No. 10,849,908, 11,007,201, and 12,115,166), successfully invalidating claims of the '908 and '201 patents at the PTAB. This ongoing PGR for Patent 12,569,491 suggests a continued strategic effort by Neurocrine to clear the intellectual property landscape for its own products or to impede Spruce's competitive offerings, particularly as Spruce advances its lead CAH candidate, Tildacerfont, through clinical trials. The case highlights the critical role of PTAB proceedings in competitive biopharmaceutical landscapes, especially for rare disease indications.

Key Legal Developments and Outcome for PGR2026-00059

This report focuses on Post-Grant Review (PGR) proceeding PGR2026-00059, initiated by Neurocrine Biosciences, Inc. against Spruce Biosciences Inc., challenging US Patent 12569491. As of today's date, 2026-06-19, this PGR is in its early stages and is currently awaiting a decision on institution.

Chronological Summary of Legal Developments:

1. Filing & Initial Pleadings:

• PGR Petition Filed (2026-06-18): Neurocrine Biosciences, Inc. filed a petition for Post-Grant Review (PGR) against Spruce Biosciences Inc., challenging the validity of US Patent 12569491. The case is docketed as PGR2026-00059 at the Patent Trial and Appeal Board (PTAB) of the U.S. Patent and Trademark Office. The petition is the initial pleading in a PGR proceeding, laying out the grounds on which the petitioner believes the patent claims are unpatentable.

2. Current Posture:

• Pending Institution Decision: The PGR is currently in the pre-institution phase. Following the filing of the petition, the PTAB will issue a "Notice of Filing Date Accorded" to officially begin the statutory timelines. The Patent Owner, Spruce Biosciences Inc., then has an optional period (typically up to three months after the filing date notice) to file a preliminary response. Subsequently, the PTAB is mandated to issue a decision on whether to institute the PGR trial within approximately six months from the petition's filing date or within three months of the preliminary response. As the petition was filed very recently (June 18, 2026), the institution decision has not yet occurred.

Parallel PTAB and District Court Proceedings (Contextual Information):

It is important to distinguish this specific PGR (PGR2026-00059 concerning US Patent 12569491) from other related proceedings between the same parties. Neurocrine Biosciences, Inc. and Spruce Biosciences, Inc. have been involved in other patent disputes:

• Prior PTAB Proceedings: Neurocrine Biosciences, Inc. previously petitioned for PGRs against Spruce Biosciences Inc. involving US Patents 10,849,908, 11,007,201, and 12,115,166. In those earlier proceedings, the PTAB issued decisions invalidating all claims of US Patents 10,849,908 and 11,007,201. The PGR concerning US Patent 12,115,166 remained pending as of June 2025.
• District Court Litigation (D. Del. Case No. 1:25-cv-00059-JDW): Neurocrine Biosciences, Inc. also filed a declaratory judgment action against Spruce Biosciences, Inc. in the U.S. District Court for the District of Delaware (Case No. 1:25-cv-00059-JDW). This case was filed on January 14, 2025, and concerned US Patent 11,344,557, in addition to the patents involved in the earlier PTAB proceedings. The district court granted Spruce's motion to dismiss for lack of subject matter jurisdiction on June 9, 2025, ruling that Neurocrine failed to demonstrate an affirmative act by Spruce asserting its patent rights.

These prior proceedings demonstrate a history of patent validity challenges between Neurocrine and Spruce, but PGR2026-00059 is a new and distinct challenge specifically targeting US Patent 12569491.

Given the nascent stage of PGR2026-00059, there have been no developments related to pre-trial motions of substance, claim construction, discovery milestones, trial events, or final decisions for this specific proceeding. The next key development will be the PTAB's decision on whether to institute the PGR.

As of June 19, 2026, the specific counsel of record for Neurocrine Biosciences, Inc. in the Post-Grant Review (PGR) proceeding PGR2026-00059 has not been definitively identified through public web searches of PTAB dockets.

While Neurocrine Biosciences, Inc. has been involved in prior litigation and PTAB proceedings against Spruce Biosciences Inc., including a District of Delaware case (1:25-cv-00059) and a previous PGR (PGR2025-00032) where Kristie Sawert was listed as petitioner counsel, the attorney appearances for the newly filed PGR2026-00059 are not yet clearly public. The case was only filed on June 18, 2026, and the petition is awaiting a decision on institution. Therefore, counsel may not have formally appeared or their appearance may not yet be reflected in publicly accessible databases.

As of June 19, 2026, with the Post-Grant Review (PGR) proceeding PGR2026-00059 having been filed only yesterday, formal appearances by counsel for Spruce Biosciences Inc. on the Patent Trial and Appeal Board (PTAB) docket are likely not yet publicly available or processed.

However, in a closely related district court patent case, Neurocrine Biosciences, Inc. v. Spruce Biosciences, Inc., No. 1:25-cv-00059-JDW (D. Del. Jun. 9, 2025), the following attorneys represented Spruce Biosciences, Inc.:

• David Ellis Moore (Lead Counsel)
  • Firm: Potter Anderson & Corroon, LLP, Wilmington, Delaware.
  • Relevant experience: A partner at Potter Anderson & Corroon, LLP, Moore regularly represents clients in intellectual property litigation, particularly in the District of Delaware.
• Bindu Ann George Palapura (Counsel)
  • Firm: Potter Anderson & Corroon, LLP, Wilmington, Delaware.
  • Relevant experience: Palapura is associated with Potter Anderson & Corroon, LLP, and was involved in the related patent dispute for Spruce Biosciences.
• Emily Shingle (Counsel)
  • Affiliation: While a specific firm is not listed in the provided snippets, Emily Shingle appeared as counsel for Spruce Biosciences, Inc. in the related district court case, likely in an of counsel or pro hac vice capacity.

It is possible, though not confirmed for this specific PGR, that Spruce Biosciences Inc. may retain these attorneys or their firm for representation in the ongoing PTAB proceeding given their prior involvement in related patent litigation concerning the same parties.